Sheet clamping device



June 27, 1944; H. w. KOST 2,352,392

. SHEET CLAMPING DEVICE Filed Aug. 4, 1943 Patented June 27, 1944 UNITED STAT 2,352,392 sneer cLAMPm o Device Harold W.Kost, Birm1ngham,-Mich., as'signcr to DetroitHai-vester Com corporation of Michigan Dany, Detroit, -Mich.,'a'

Application August 4, 194 3 Serial No.

This invention relates to fasteningdevices but more particularly to fasteners for holding together two or more sheets or strips of metal or the like.

It is often desirable to clamp together a plurality of superimposed sheets or strips of metal or the like to enable them to be uniformly cut to length or for some other purpose. Fasteners of this general character are widely used in the aircraft industry and heretofore a stack of sheets has been held together by inserting bolts through registering apertures in the sheets and applying a wing nut to the threaded end portion of the bolt. Such fasteners are objectionable not only because of the time consumed in applying the wing nuts and removing them after the work has been accomplished but also in the case of some metals employed in the aircraft industry, the nuts may be tightened to such an extent as to deform the metal sheet or strip.

An object is to overcome the difliculties above mentioned and to produce a new and improved fastener which can be quickly applied and removed and which satisfactorily clamps the metal sheets in assembled relation without injury or deforming of the surface.

Other objects and advantages of the invention will hereinafter appear and for purposes of illustration but not of limitation, an embodiment of the invention is shown on the accompanying drawing in which Figure l is an enlarged perspective view of the fastening device applied to a stack of sheets, the fastener being shown in clamping position;

Figure 2 is a top plan view of the fastener shown in Figure 1;

Figure 3 is a side elevation of the fastener shoiwing the fastener in process of being applied; an

Figure 4 is a side elevation partly in section showing the fastener applied to a stack of sheets prior to the shifting movement of the fastener, a. tool for applying the fastener being indicated by broken lines.

The illustrated embodiment of the invention comprises a platform P on which is mounted a plurality of superposed sheets S of metal or the like forming a stack. It is desired to hold or clamp the sheets S securely to the platform P in order that they can be cut to length in one operation or for some other purpose. For this purpose, the sheets S and platform P are provided with apertures which when brought into register, receive a pin B, the head H of which abuts against the underside of the platform P. The pin B is of sufficient length not only to project through the sheets S but to provide a portion extending above the same. The upper end portion-of the pin B is pointed, as indicatedatE and spaced a. short distanceffrom the pointedendis -a-lreduced neck 'N, the sides of the neck being in parallel relationship and spaced from each other substantially the thickness of the fastener arm as will hereinafter appear.

The sheet clamp which is adapted to be applied to the pin B is a one-piece spring metal structure having an upper flat arm I 0 and a lower flat arm II. The arms I0 and II are integrally joined by a web or metal portion I2 provided with a. loop I3 to afford the desired spring action. Normally the upper arm I0 is upwardly inclined with respect to the lower arm I I so that the two arms are in non-parallel relationship. The lower arm II is adapted .to bear flatwise against the outermost sheet S substantially as indicated.

In order to enhance the strength of the arms I0 and II, upturned flanges II are provided on each side of each of the arms.

The lower arm II is formed with a slot I5 which is elongate in a direction longitudinally of the arm. Formed in the arm I0 is a keyhole slot having a relatively large substantially annular portion I6 of a diameter slightly greater than the diameter of the pin B and a reduced portion I! which is substantially the diameter of the reduced neck N.

In practice, the arms I0 and II are engaged by a suitable tool such as indicated at T in Figure 4 to bring the arms substantially into parallel relation at which time the hole I6 alignswith the right hand portion (Figure 1) of the elongate slot I5. The fastener may then be readily slipped over the end of the pin B. As soon as the reduced neck N is encountered, the fastener is shifted laterally so that the reduced neck is disposed within the smaller opening I1 of the keyhole slot. Thus it will appear that the arm I0 is securely anchored to the pin B and the spring I3 urges the lower arm II into snug engagement with the adjacent sheet S, thus holding the sheets in the desired clamped position.

In order to facilitate the application and re moval of the fastener from the pin B, the arm III has an upturned flange or end portion I8. The arm II has an upwardly inclined portion I9 which terminates in a downturned flange 20. The flanges I8, and 20 enable the tool T above mentioned similar to a pair of pliers to be applied in order not only to move the arms Ill and II toward each other, but also to effect the shifting movement above mentioned. By providing the upwardly inclined end portion is on the arm H, ample space above the outermost sheet S is afforded to receive one of the jaws of the tool T. The tool T in general resembles a pair of pliers, the ends being hook-shaped.

From the above description, it will be manifest that a series of fasteners as above described can be employed in case the strips or sheets of metal are of any substantial length. I In this manner, the sheets can be readily and efficiently clamped in place with a minimum amount of effort and 1. The combination of a pin having a head at one end and a reduced neck adjacent the opposite end. said pin being adapted to be inserted through aligned apertures in a stack of superimposed sheets with the head of the pin engaging one side thereof, a fastener for clamping said sheets, said fastener comprising a pair of arms, an integral spring connection between said arms, said spring normally holding said arms out of parallel relationship one arm having an elongate slot extending lengthwise thereof, the other arm having a keyhole slot extending lengthwise thereof. said slots being adapted to be moved into registration when said arms are substantially parallel whereby the arms can be applied to said pin until the large portion of the keyhole slot is adjacent the reduced neck on said pin whereupon the fastener is shifted laterally to dispose the neck in. the smaller portion of the keyhole slot, said first arm bearing against the stack.

2. A sheet clamp as claimed in claim 1, in which the reduced neck is substantially the thickness of the arm having the keyhole slot, and tool engaging flanges on said arms respectively to enable same to be applied to and removed from said pin.

HAROLD W. KOST. 

